RE: Iterations in a SELECT - Mailing list pgsql-novice

From Robby Slaughter
Subject RE: Iterations in a SELECT
Date
Msg-id EPEHLKLEHAHLONFOKNHNCEPLDCAA.webmaster@robbyslaughter.com
Whole thread Raw
In response to Iterations in a SELECT  ("Scott Muir" <wsmuir@islandnet.com>)
Responses RE: Iterations in a SELECT  ("Scott Muir" <wsmuir@islandnet.com>)
List pgsql-novice
Scott,

>I'm trying to put together a select where a list dates is compared to a
>period to identify dates which aren't in the list...

Sounds like you are trying to find out what values are not in a list of
other values.
Here's my example which you can adapt (if it's what you're trying to do).
Two tables,
test and test2, each with an integer column called val and val2
respectively:

select * from test;
  val
  ---
   1
   2
   3
   5
   6
   3

select * from test2;
  val2
  ----
   3
   4

Then you do a quick subselect and...

   select * from test where val not in ((select val2 from test2));

   Result is:
     val
    -----
      1
      2
      5
      6

Is that what you're hoping to do?

I can't think of anyway to do a select and genrate a list from x to y.
Wow, that's a great one!

Hope this helps,

-Robby





I could just create a list of days in a table (like 20 years worth) and then
compare it, but I'm wondering if there is a trick where one could get
results like this

select (for i := 1 to 5) as number;

or

select i as number from for(i,1,5);

and get something like

number
------
1
2
3
4
5

Any suggestions?
Thanks
Scott.


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